Sometimes I find the vegetarian options a bit lacking. I mean, there ARE loads of non-meat options, but they tend to skew towards carbs and fat, until you go into the more expensive places. Blue Bayou, Cafe Orleans both have salmon options if I recall (though I believe they're farmed, which is an issue for some people.) There are the fruit/veggie stands throughout the park.
Bengal Grill has nice veggie skewers as mentioned.
I *think* Pizza Press has moved, but it's a great offsite option, and one of our go-tos. There's also a Jamba Juice in DTDisney that we frequent.